Semiconductor processing methods of removing conductive material
View Patent ↗The invention includes a semiconductive processing method of electrochemical-mechanical removing at least some of a conductive material from over a surface of a semiconductor substrate. A cathode is provided at a first location of the wafer, and an anode is provided at a second location of the wafer. The conductive material is polished with the polishing pad polishing surface. The polishing occurs at a region of the conductive material and not at another region. The region where the polishing occurs is defined as a polishing operation location. The polishing operation location is displaced across the surface of the substrate from said second location of the substrate toward said first location of the substrate. The polishing operation location is not displaced from said first location toward said second location when the polishing operation location is between the first and second locations. The invention also includes a semiconductor processing method of removing at least some of a conductive material from over a surface of a semiconductive material wafer. A polishing pad is displaced across an upper surface of the wafer from a central region of the wafer toward a periphery of the wafer, and is not displaced from the periphery to the central region.
1. A semiconductor processing method of eletrochemical-mechanical removing at least some of a conductive material from over an upper surface of a semiconductor substrate including a silicon wafer, the method comprising:
displacing a polishing operation location across the upper surface of the substrate from a central region of the substrate toward a periphery of the substrate and not displacing the polishing operation location from the periphery to the central region, the polishing operation location being defined by a location of a polishing pad relative to a surface of the substrate; and
rotating both the polishing pad and the substrate separately from the displacement.
2. The method of claim 1 wherein the polishing pad is rotated in counter-rotary manner relative to the rotation of the substrate.
3. The method of claim 1 wherein the polishing pad comprises a flexible material and has peripheral edges that are raised relative to a center of the polishing pad.
4. The method of claim 1 wherein a polishing surface of the polishing pad extends over only a portion of the surface of the substrate.
5. A semiconductor processing method of removing conductive material, comprising:
providing a silicon wafer having a conductive material thereover, the wafer comprising an upper surface and an outer periphery around the upper surface, the conductive material extending across the upper surface of the wafer and to about the periphery;
electrochemically removing at least some of the conductive material with a polishing pad having a surface in abrasive contact with only a portion of the conductive material;
displacing the polishing pad across the upper surface of the wafer during the removing, the displacing being only from a central region of the wafer surface toward the periphery of the wafer;
rotating at least one of the polishing pad and the wafer separately from the displacement; and
providing an electrical circuit through at least a portion of the conductive material during the removing, the circuit extending between at least one second electrical connection in electrical contact with a polishing surface of the polishing pad and at least one first electrical connection in direct electrical contact with conductive material only at the periphery.
6. The method of claim 5 wherein the polishing pad is displaced circularly around the central region to define rings which progress increasingly outward toward the periphery of the wafer.
7. The method of claim 5 comprising rotating both the polishing pad and the wafer where the polishing pad is rotated in counter-rotary manner relative to the rotation of the wafer.
8. The method of claim 5 wherein the polishing pad comprises a flexible material and has peripheral edges that are raised relative to a center of the polishing pad.
9. The method of claim 5 wherein a polishing surface of the polishing pad extends over only a portion of the surface of the substrate.